(Reuters) - Warburg Pincus and the Ontario Teachers’ Pension Plan (OTPP) are exploring a sale of Chisholm Energy, an oil and gas exploration and production company focused on the Permian basin, people familiar with the matter said on Monday. The two owners are working with an investment bank to run the sale process for Chisholm Energy, according to the sources, who noted the company is expected to attract a valuation approaching $1 billion. There is no guarantee Chisholm will be sold and one or both owners could retain their holding, cautioned the sources, who spoke on condition of anonymity to discuss private information. With U.S. crude prices up over 50% since the start of the year, mergers and acquisitions in the oil sector have flourished. Buyout firms seeking to use the positive market backdrop to offload past investments are helping to fuel the dealmaking boom. Chisholm Energy was formed in 2016. As part of its backing, Warburg extended the firm a $500 million line of equity to fund acquisitions. The Fort Worth, Texas-based company has built a portfolio of acreage in the New Mexico portion of the Delaware basin, according to its website. Warburg Pincus and Ontario Teachers declined to comment. Chisholm Energy did not respond to a request for comment.